First, RV anti-freeze is a propylene based type antifreeze. This means you should use the Thexton Part #100 or #107 antifreeze. The term “Burst Protection” is used and usually in fine print on most RV antifreeze containers. A minus 50°F identification on RV antifreeze will actually test about +25°F on our testers. Burst Protection simply means that the pipes in your RV won’t break at -50°F, it will although slush at about +25°F. If this mixture was in your vehicle, the water pump would not be able to move the mixture and the engine would overheat. The RV antifreeze container with -100°F on them will test reasonable close to the numbers printed in our instructions.

Example: a 50/50 mixture of -100°F RV antifreeze will test at about -25°F